I never used to 'get' the Naim thing until early last year.
Occasional (but regular) exposure to various Linn/Naim systems (dealers, shows, friends systems etc.) over the last 30 years convinced me they were harsh, headache inducing, and largely mono sounding and owned by fanatics.
It never even occurred to me that they could perform well at anything other than VERY LOUD volume levels because that is how everyone played them. The trademark of the Linn/Naim demo was always someone shouting over the music (usually Dire Straits or some godawful Linn or Naim demo disc) telling you how great it was!
The worst was a bi-amped pair of Linn Saras with NAP 250s and (of course) the inevitible Sondek/Ittok/Troika. The bass was like someone panel beating metal sheets, and when the guy produced his copy of 'Telegraph road' and turned the volume up I had to run away feigning illness or a forgotten appointment or something. (He was a 'shouter' too and delighted in giving loud running commentaries on how amazing it was!)
Second worst Naim experience was in the small cellar/crypt-like demo room at the (now defunct) Chichester Hifi. Listening to Robert Palmer playing on an original Nait with Linn Kans and a Linn Sondek. Needless to say, the proprietor (a nice guy called Rob) was shouting over it at us and in such a tiny space it was terrible. I went upstairs leaving my friend (who was buying that day) and hung around upstairs listening to something more pleasant playing on a Quad/Heybrook system.
Not suprisingly all this coloured my opinion of Naim for a very long time. (Even up until a couple of years ago when I first heard the Nait 5i/CD5i).
I finally lost my pre-conditioned responses after hearing the Nait XS and then getting a home demo of my current system. (With my old Rega R3's)
The Nait XS is fuller and fatter and warmer and a tad smoother so maybe you would be best trying that out with your speakers. (I first heard the Nait XS - accidently - with a pair of Rega RS1s and a CD5X and they sounded splendid together.)
I can empathise with people who assume Naim is harsh but I am certain the modern Naits (5i and XS) are far smoother, more pleasant and more musical. I rarely play anything really loud, never play Dire Straits, and never shout at people over the music.
(Not a fanatic either given that I aspire to all non-Naim equipment - if I am ever wealthy enough - and have no Naim upgrade path planned at all.)